Light-emitting device and image display apparatus using the same

Abstract

A light-emitting device includes a light-emitting layer and a fine structure layer that opposes the light-emitting layer, and light generated in the light-emitting layer passes through the fine structure layer. In the light-emitting device, the fine structure layer includes a plurality of first medium portions and a second medium that has a different refractive index from a refractive index of the first medium, and the plurality of first medium portions are each surrounded by the second medium in an in-plane direction of the fine structure layer. In the light-emitting device, each first medium portion is formed to have a rotated ellipsoidal shape, which has a major axis extending in a direction perpendicular to a surface opposite the light-emitting layer, and is defined by a path of an ellipse rotated about the major axis as a rotation axis.

What is claimed is: 
     
         1 . A light-emitting device comprising:
 a light-emitting layer; and   a fine structure layer that opposes the light-emitting layer, light generated in the light-emitting layer passing through the fine structure layer,   wherein the fine structure layer includes
 a plurality of first medium portions, and 
 a second medium region, the second medium region having a refractive index different from a refractive index of the first medium portions, 
   wherein the plurality of first medium portions are each surrounded by the second medium region in an in-plane direction of the fine structure layer,   wherein each first medium portion is formed to have a rotated ellipsoidal shape, the rotated ellipsoidal shape having a major axis that extends in a direction perpendicular to a surface that opposes the light-emitting layer, the rotated ellipsoidal shape being defined by a path of an ellipse rotated about the major axis as a rotation axis.   
     
     
         2 . The light-emitting device according to  claim 1 ,
 wherein the plurality of first medium portions are arranged in a triangle lattice shape in the surface, and a lattice constant of the triangle lattice shape is from 1 μm to 3 μm.   
     
     
         3 . The light-emitting device according to  claim 2 ,
 wherein each of the plurality of first medium portions is arranged such that the center of gravity thereof is positioned at a corresponding lattice point in the triangle lattice shape.   
     
     
         4 . The light-emitting device according to  claim 1 ,
 wherein each of the plurality of first medium portions is aperiodically arranged in the surface.   
     
     
         5 . The light-emitting device according to  claim 1 ,
 wherein the ellipticity of the rotated ellipsoidal shape is smaller than 1.43.   
     
     
         6 . The light-emitting device according to  claim 1 , further comprising:
 a front plate, light generated in the light-emitting layer passing through the front plate,   wherein the fine structure layer is positioned between the light-emitting layer and the front plate.   
     
     
         7 . The light emitting device according to  claim 6 ,
 wherein the light generated in the light-emitting layer and passing through the front plate is refracted at an exit surface of the front plate at an angle equal to or less than the critical angle.   
     
     
         8 . An image display apparatus comprising:
 a plurality of light-emitting devices arranged in a matrix shape,   wherein each light-emitting device comprises the light-emitting device according to  claim 1 .